'recommend deletion' instead of 'delete'

Question

In a single row of 3 reviews in the Low Quality review queue today the third review would not let me select Delete, although the others would.

I didn't go below the Trusted User between those reviews, so I assumed this is caused by the "state" of the answer or the other reviews.

One of the other reviews had a "Looks OK" from another reviewer as well, so I assume that is not it.

This last review did have a positive score. Is that why I could only "Recommend deletion" and not "Delete"? Is that decrease of privileges documented somewhere in the help pages or somewhere else?

(Shortly after, @slm used his moderator powers to delete all 3 posts).

Answer 1

From the documentation on Low Quality Review Queue:

Post accumulates 3 Delete votes (can only happen when post scores <= 0 and reviewers have >= 20K rep).

From a question page, a 20K user can only cast delete votes on negatively scored answers. From the review, they are also allowed to cast them on zero-scored questions:

Review gives you a bit of a boost by allowing you to vote to delete 0-scored answers. This is done just to save you the step of having to down-vote them first and then vote to delete.

But if the answer score is positive, nobody other than a mod (or the post owner) can cast a vote to delete it. This is why your review decision is a recommendation. When 6 users recommend deletion on such a post, the following happens, per the documentation:

mark flags "helpful". If the post scores > 0 then raise DisputedLowQuality mod flag

So the final decision rests with a moderator then.